If this is your first visit, be sure to
check out the FAQ by clicking the
FAQ link. You may have to register
before you can post: click the register link above to proceed. To start viewing messages,
select the forum that you want to visit from the selection below. NOTE! If you get a "spammer warning" notice on registration, try MODIFY your prefered handle/nickname!

I've been advised that keeping a battery permanently hooked up to an optimate or similar won't actually help prolong battery life...it doesn't harm a battery to be discharged now and again, just not left to fully discharge to a flat state. I leave mine off for 4 weeks at a time with no ill effects but over the winter it gets hooked up and left until charged then disconnected for 3 or 4 weeks before trickle charging to top it up every 3 or 4 weeks. Even optimates (at least the one I have) continue to charge at low amps when the battery is full, and this does neither the battery nor the charger any good. I have another which dumps current once it detects a full battery but it's still using electric all the time so with my green hat on, I think it's poor practice to leave any charger on all the time.

There is often a misconception that leaving a battery connected for a significant amount of time is detrimental to the life of the battery! It is NOT a CHARGER you need but a BATTERY TENDER. A battery tender simulates daily usage by discharging to differing levels and recharging your battery to full only delivering a subsequent charge when and if it is required before the next scheduled cycle. You can leave a tender fitted for as long as you wish without ill effect. If however you do not have a sealed battery a periodic check of battery electrolyte level even in the case of a tender is strongly recommended.

Chargers are so yesterday, outdated and unnecessary where there are a myriad of tenders on the market for about half the price of a replacement battery.

Last edited by K9F; 06-13-2018 at 04:17 PM.

IF YOU GO THROUGH LIFE WITH YOUR HEAD IN THE SAND.....ALL PEOPLE WILL SEE IS AN ARSE!!
TREAT EVERY DAY AS YOUR LAST.....ONE DAY YOU WILL BE RIGHT!!

The Following User Says Thank You to K9F For This Useful Post:

Mine is a tender but I still don't leave it on all the time as I don't see the need, nor in needlessly using electric. My battery's been off the tender for probably a couple of months now. When I have any hint of heavy starting, it goes back on and I let it do its thing for a good 2 to 3 days and it's usually good as new. It's a fallacy I think that batteries need to be constantly hooked up to tenders...they don't unless you have something drawing a lot of current, like some after market alarm systems. During the summer, most bike owners will use a bike at least weekly I'd have thought and a few good runs will keep the battery in good enough shape. It's lots of short runs that'll do the damage to batteries as well as engines.

I agree too. Never thought it was good to leave any battery on charge all the time, so haven't done it with my Iron. I put the charger on every 3-4 weeks till it shows a full charge . Did same with my honda and had batteries last up to 9yrs.

Memory effect is the old NiMH(nickel Metal Hydride) rechargeable. Don't think they ever made these in larger than power tool sizes. Draining a battery is only helpful with the NiMH or some Lithium Ion. I would not put a Li batt in my Harley, tho. It shakes too much and a 400CCA Li batt would burn it to the ground quickly if it failed. I mean too fast for you to park it and jump off of it. Li goes up like a freaking roman candle. Most batts are AGM nowadays. Gelled meshed vs water. No maintenance, no topping off, and the design doesn't lend itself to plate breakage. But it can still sulfate if it is drained too much(80% vs 50 for lead acid). It also charges 5X faster than the old style.